To investigate the surgical technique of microendoscopic treatment of giant lumbar disc herniation and to summarize its treatment results. METHODS: From September 2001 to June 2005, 31 patients with giant lumbar disc herniation confirmed by CT or MRI were treated by microendoscopy. RESULTS: The follow-up ranged from 6 to 36 months, with an average of 18 months, and the efficacy was evaluated according to Nakai’s criteria, with an excellent rate of 87.1%, all without complications such as nerve root injury and dural tears. CONCLUSION: Microendoscopic treatment of giant lumbar disc herniation is technically and operationally feasible with satisfactory clinical results. Limited and minimally invasive spine surgery is one of the trends in the development of surgery. In recent years, posterior microendoscopic surgery of the spine has developed rapidly, and the indications for surgery have been expanded. 718 cases of lumbar disc herniation were treated by microendoscopy in our hospital from September 2001 to June 2005, including 31 cases of giant lumbar disc herniation, with satisfactory results, as reported below. Data and methods There were 19 male cases and 12 female cases in this group; age ranged from 28 to 56 years old, average 40 years old; duration of disease ranged from 2d to 3 years, acute onset in 26 cases, average duration of disease 3 days, including 8 cases of lumbar sprain and 18 cases of onset after massage. There were 5 cases with non-acute onset and an average duration of 5.2 months, including 1 case of lumbar sprain and 1 case of heavy lifting injury, and the other 3 cases had no obvious causative factors. All of them were single interstitial protrusions, including L4/513 cases and L5/S 118 cases; 21 cases were of central type and 10 cases were of paracentral line. The herniated nucleus pulposus was located under the posterior longitudinal ligament in 11 cases, and broke through the posterior longitudinal ligament and prolapsed into the spinal canal in 20 cases. Low back pain with unilateral lower limb pain and numbness in 9 cases, bilateral lower limb pain and numbness in 22 cases, numbness in the saddle area in 18 cases, major and minor bowel obstruction in 9 cases, and incomplete paraplegia in 1 case. In all cases, CT or MRI examination showed that the herniated nucleus pulposus occupied more than 1/2 of the sagittal diameter of the spinal canal and confirmed the diagnosis of giant lumbar disc herniation, and there was no stenosis of the lateral saphenous fossa or central spinal canal in all cases. Preoperative procedure A 12-gauge needle was inserted into the interspinous lesion for radiographic positioning, and epidural anesthesia was administered in the prone position with the abdomen padded. If bilateral lower limb pain is required, a posterior median incision is made and the skin is moved to create two working channels on the left and right sides. A guide needle is placed in the lesion gap to probe the lower edge of the lesioned vertebral plate, and the paravertebral muscles are expanded step by step to establish a working channel, the free arm is fixed on the surgical bed rail, a microscopic camera system is installed, and the monitor is adjusted to provide a clear image. The nerve root and intervertebral disc adhesions were carefully separated, the nerve root and dura mater were drawn medially to reveal the protruding disc, the fibrous ring was cut with a sharp knife to remove the protruding nucleus pulposus, the nerve root hook was probed and the posterior edge of the entire vertebral body was flat, and there was no protruding disc. The degree of root relaxation, after decompression can generally move about 0.5cm is satisfactory for relaxation. Intraoperative bleeding was stopped by compression with epinephrine brain cotton. Dexamethasone 5mg was injected around the nerve root. 1ml of bioprotein gel was injected at the bone window and the working channel was removed. Generally no drainage is placed and absorbable thread is sutured intradermally. Postoperative antibiotics, mannitol and dexamethasone were routinely administered for 3-5 d. Straight leg raising exercises were performed on postoperative day 2, lumbar brace was worn to bed for 2-3 d, and functional exercises for the lumbar back muscles were started after 7-10 d.